<!DOCTYPE html>
<html lang="en">
 <head>
  <meta charset="UTF-8">
  
 </head>
 <body>
  <script>
 var mycars = ["Saab","Volvo","BMW"];
    for(key in mycars){
        document.write(key+':'+mycars[key]);
        document.write('<br/>');
    }

  </script>
 </body>
</html>
